<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        //同：1 7
        //微：2 3 8 4 6 5
        //宏：0
        setTimeout(() => {
            console.log(0);
        }, 0)
        new Promise((resolve, reject) => {
            console.log(1);
            resolve();
        }).then(() => {
            console.log(2);
            new Promise((resolve, reject) => {
                console.log(3);
                resolve();
            }).then(() => {
                console.log(4);
            }).then(() => {
                console.log(5);
            })
        }).then(() => {
            console.log(6);
        })
        new Promise((resolve, reject) => {
            console.log(7);
            resolve();
        }).then(() => {
            console.log(8);
        })
    </script>
</body>

</html>